JPH08171085A - Compound eye display device using liquid crystal panel and driving signal adjusting method for the device - Google Patents

Abstract

PURPOSE: To reduce the fatigue of an observer's eye by decreasing the difference between a left and a right images by the secular change of a LCD (liquid crystal display). CONSTITUTION: This device comprises plural liquid crystal display means 3a, 3b for displaying image information, liquid crystal driving means 9a, 9b generating a driving signal for the display means and changing the amplitude of the driving signal, a common electrode potential generating means giving a common electrode potential to the liquid crystal display means 3a, 3b, an image signal generating means 16 for generating an adjusting image signal and photometric means 11a, 11b for measuring the luminances of the liquid crystal display means 3a, 3b, first, an image signal for adjusting a common electrode potential is supplied from the image signal generating means 16 to the respective liquid crystal display means 3a, 3b through the liquid crystal driving means 9a, 9b. A control means 13, for adjusting the common electrode potential based on the outputs of the photometric means 11a, 11b at this time, thereafter, supplying an image signal for adjusting the amplitude of the driving signal from the image signal generating means 16 to the liquid crystal display means 3a, 3b and adjusting the amplitude of the driving signal in the driving means 9a, 9b based on the outputs of the photometric means 11a, 11b, is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compound eye display device in which an image is displayed on each of a plurality of display means and the images are observed by the left and right eyes, respectively. The present invention relates to an apparatus using a display device and a drive signal adjusting method thereof.

[0002]

2. Description of the Related Art In a conventional liquid crystal display device, in order to prevent image sticking of the liquid crystal display device when driving the liquid crystal display device, FIG.
As shown in (a), a constant potential is applied to the common electrode, and a drive signal whose polarity is inverted around the constant potential is given to each pixel electrode of the liquid crystal display device in a predetermined cycle. However, in actuality, due to the influence of the parasitic capacitance inside the pixel electrode, the drive signal is lowered by ΔV as shown in FIG. 7B, which causes flicker and lowers the contrast ratio of the display image. It has been known. As a countermeasure, when driving the liquid crystal display device as shown in FIG. 7C, the common electrode potential (Vcom) is made slightly lower than the signal center of the drive signal.

[0003]

However, when the liquid crystal display device is driven for a long time, .DELTA.V gradually increases, so that the optimum value of the common electrode potential Vcom for driving the liquid crystal display device also gradually increases. Will fall to. Further, since the VT characteristic (relative transmittance characteristic) of a normal liquid crystal display device is slightly different for each liquid crystal display device, even if the same drive signal is input, the contrast ratio does not become the same. The VT characteristic and the change in ΔV with time vary depending on the individual liquid crystal display device.

As a result, in a compound eye display device or the like which drives a plurality of liquid crystal display devices at the same time, there is a problem in that left and right images gradually differ from each other, and the eyestrain of an observer remains.

Here, the contrast ratio is the ratio of the brightness when a 100% white image is displayed and the brightness when a black image is displayed on the liquid crystal display device, and is expressed by the following equation.

[0006]

[Equation 1]

The present invention has been made in view of the above-mentioned problems in the conventional example, and it is possible to reduce the difference between the left and right images due to the aging of the LCD, and reduce the fatigue of the eyes of the observer. An object of the present invention is to provide a compound eye display device and a drive signal adjusting method thereof.

[0008]

In order to achieve the above object, in the present invention, a plurality of liquid crystal display means for displaying image information and a drive signal for driving the plurality of liquid crystal display means are generated, and In a compound eye display device having a liquid crystal driving means capable of changing the amplitude of the drive signal and a common electrode potential generating means for applying a common electrode potential to the plurality of liquid crystal display means, at least one or more adjusting devices are provided. By providing an image signal generating means capable of generating an image signal and a photometric means for measuring the brightness of the liquid crystal display means, the common electrode potential is individually adjusted for the plurality of liquid crystal display means, and thereafter, The liquid crystal drive signal is adjusted so that the difference in brightness between the plurality of liquid crystal display means is reduced.

[0009]

The adjustment of the liquid crystal drive signal is performed, for example, when the power is turned on or every time the operation time of the device exceeds a predetermined time. As described above, by periodically performing the adjustment even after the compound-eye display device is manufactured, it is possible to reduce the difference between the left and right images due to the change over time of the LCD and reduce the user's eye fatigue.

The liquid crystal drive signal may be adjusted by providing an instructing means such as an adjustment instructing switch and the like when the instructing means gives an instruction. This makes it possible to make adjustments when the user feels a difference between the left and right images.

Further, storage means for storing various adjustment data of the compound-eye display device and measurement means for measuring the drive time of the liquid crystal display means are further provided, and the storage means stores the total drive time of the liquid crystal display means. By recording, when the driving time of the liquid crystal display means reaches a predetermined time when the compound eye display device is powered on, the adjustment operation is performed, and the adjustment value is stored in the storage means, Also,
When the drive time of the liquid crystal display means has not reached a predetermined time, the common electrode potential and the amplitude of the liquid crystal drive signal may be adjusted according to various data stored in the storage means. In this case, when the driving time of the liquid crystal is very short, the adjusting operation is omitted, so that the time from the power-on to the shift to the usable state can be shortened.

[0012]

EXAMPLE 1 FIG. 1 shows the structure of a compound eye display device according to an example of the present invention. In FIG. 1, 1a and 1b are signal input sections for inputting video signals, and 3a and 3b are liquid crystal display sections (LCD) for displaying video signals. Denoted at 5a and 5b are decoder units for converting the video signals input from the signal input units 1a and 1b into RGB signals, respectively, and 7a and 7b.
b is a signal processing unit for performing gamma processing or the like on the video signal converted into RGB signals by the decoder units 5a and 5b, and 9a and 9b are RGB signals subjected to signal processing by the signal processing units 7a and 7b. LCD 3a, 3b
Is a driver unit that outputs an RGB drive signal and a common electrode potential to drive the. RGB of the driver units 9a and 9b
The structure of the portion for generating the drive signal is as shown in FIG.
In the driver section of FIG. 2, first, the input signal (FIG. 3A)
Then, the inverting unit 91 and the non-inverting unit 92 generate an inverting signal and a non-inverting signal. The amplitudes of the inverted signal (FIG. 3B) and the non-inverted signal (FIG. 3C) are determined by the resistance value of the variable resistor VR1. Next, the inverted signal and the non-inverted signal are switched every fixed period (for example, 1H period).
It is output as an LCD drive signal as shown in (d). The amplitude of this LCD drive signal is determined by the resistance value of the variable resistor VR2. In FIG. 1, 11a and 11b are LC
A photometric element for measuring the brightness of the surface of D3a, 3b.

Further, 13 is the decoder section 5a, 5
b, the signal processing units 7a and 7b, the driver units 9a and 9b, and the photometric elements 11a and 11b. Then, 14 is a power supply for driving the entire compound eye display device,
A power switch 5 controls the supply of electric power from the power source 14. Further, 16 is an image signal generation unit whose operation is controlled by the control unit 13 and which can selectively output a 100% white image signal, a 50% white image signal and a black image signal, and 17 is for storing various data. A memory 18 is a memory control unit that reads and writes data from and to the memory 17.

Next, the operation of the apparatus shown in FIG. 1 will be described. First, the procedure for displaying the video signal on the LCD is as follows. The video signal input to the signal input unit 1a is separated into a luminance component and a chroma component by the decoder unit 5a and further converted into an RGB signal. Then, the converted RGB signals are each subjected to gamma correction suitable for liquid crystal display in the signal processing unit 7a and supplied to the driver unit 9a.
In the driver unit 9a, as shown in FIG. 3, an inverted signal and a non-inverted signal having a predetermined amplitude are supplied to the supplied video signal.
Are generated and both of them are subjected to a constant cycle (1H or 1V
The driving signal for the LCD 3a is created by switching the setting every time. The drive signal thus generated is L
By being input to the CD 3a, the LCD 3a is driven and an image is displayed. This operation is the same for the video signal input to the signal input unit 1b, and the LCD 3 is passed through the decoder unit 5b, the signal processing unit 7b, and the driver unit 9b.
It is displayed in b.

In the first embodiment, LCDs 3a and 3b are used.
If the photometric elements 11a and 11b are installed at positions where the surface brightness of the device can be measured and the user does not hinder the observation of the image displayed on the LCD, and the power switch 15 is turned on to supply the power, the “common electrode By performing "potential adjustment" and "driving signal amplitude adjustment" promptly, ΔV and V-
It is possible to reduce the fatigue of the eyes of the observer due to the change of the T characteristic with time.

Next, the common electrode potential adjusting operation and the drive signal amplitude adjusting operation in the apparatus of FIG. 1 will be described with reference to the flowchart of FIG. <Common Electrode Potential Adjustment> The controller 13 controls the image signal generator 1
6, a white 50% image signal whose polarity is inverted in the field cycle is input to the driver unit 9a and displayed on the LCD 3a (see FIG. 4).
Then, the brightness of the LCD surface is sampled at 60 KHz by the photometric element 11a (S112).
Then, the sampling result is stored in the memory for a predetermined period, and the brightness of the LCD surface for each field is compared (S113). LCD 3a by driver unit 9a
Of the LCD 3 while shifting the common electrode potential Vcom of
Repeatedly compare the surface brightness of a, and LCD
The common electrode potential that minimizes the difference in surface brightness of 3a is obtained, and the common electrode potential Vcom of the driver unit 9a is set to that value (S114).

This common electrode potential adjustment operation is performed for each LCD.
And the driver section, LCD3
Similar adjustment operations are performed for b and the driver unit 9b.

<Drive signal amplitude adjustment> The control unit 13 controls the image signal generation unit 16 to output a black image signal to the driver units 9a and 9a.
Input to b and display a black image on the LCDs 3a and 3b (S121 in FIG. 4). Then, the brightness of the display image is set by the photometric elements 11a and 11b (S122), and the left and right LCs are set.
After adjusting R2 of the driver units 9a and 9b so as to minimize the difference in brightness between D3a and 3b (S123), a 100% white image is similarly displayed on the LCDs 3a and 3b (S12).
4), so that the difference in brightness is minimized.
R1 of a and 9b is adjusted (S125, S126).

In the adjustment of the first embodiment, a switch for selecting whether or not to execute the adjustment operation may be provided, and the adjustment may be performed only when the switch is selected.

Embodiment 2 FIG. 5 shows the structure of a compound eye display device according to another embodiment of the present invention. This device is obtained by adding a timer 19 to the block diagram of FIG. The timer 19 is controlled by the control unit 13, measures the time during which the LCDs 3a and 3b are driven by the driver units 9a and 9b, and is reset when the power is turned off. In addition, in the second embodiment, the memory 17 is stored in the memory 17 in addition to various adjustment data.
The total drive time of a and 3b is stored.

Next, the operation of the second embodiment will be described with reference to the flowchart of FIG. First, in the second embodiment, the operation of each unit from the input of the image signal to the signal input units 1 and 2 to the display on the LCDs 3a and 3b is the same as that of the first embodiment. For adjusting the contrast ratio, in the second embodiment, the control unit 13 reads the LCD drive time stored in the memory 17 when the power is turned on, and determines whether the LCD drive time exceeds a predetermined time. (S201 in FIG. 6). Here, when the LCD drive time exceeds the predetermined time (Y in S201), the adjustment images (black image and white 100% image) are displayed on the left and right LCDs 3a and 3b as in the first embodiment. The contrast ratio is displayed and adjusted (S204), and after the adjustment is completed, the control unit 13 updates the adjustment values of R1 and R2 stored in the memory 17 to new adjustment values (S205). Next, the control unit 13 sets the total of the LCD drive time stored in the memory 17 to 0 (S206), and starts the LCD drive time measurement by the timer 19 (S207). When the LCD drive time is within the predetermined time (N in S201), R1 and R2 stored in the memory 17 are stored.
Read the adjustment value of (S202), and the driver units 9a, 9
b is adjusted (S203). After these adjustment operations are completed, the control unit 13 starts measuring the LCD drive time by the timer 19 (S207).

Then, the compound-eye display device enters the image display mode (S208), and can be used.

When the controller 13 detects that the power switch 15 is off when the power is turned off (S209),
The control unit 13 adds the LCD drive time measured by the timer 19 to the LCD drive time stored in the memory 17 to update the LCD drive time of the memory 17 (S21).
0). Then, after the LCD drive time is updated,
The power supply from the power source 14 is stopped.

By adjusting the contrast ratio according to the driving time of the LCD as described above, it is possible to shorten the waiting time for adjustment when the power is turned on and to supply an image with a small difference in brightness to the left and right eyes. It is possible and can reduce eye strain.

In the second embodiment, if the LCD drive time does not exceed the predetermined time, the contrast ratio adjusting operation need not be performed.

[0026]

As described above, according to the present invention, the contrast ratio of the left and right liquid crystal display means is adjusted when the power is turned on or at a predetermined cycle, and further as desired, so as to cause a change with time of the LCD. It is possible to reduce the difference between the left and right images to reduce the eyestrain of the observer.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a compound eye display device according to an embodiment of the present invention.

FIG. 2 is a circuit diagram showing a configuration of a liquid crystal driver unit in FIG.

3 is a waveform diagram of each part of the liquid crystal driver unit of FIG.

4 is a flowchart showing the operation of the apparatus of FIG.

FIG. 5 is a block diagram showing a configuration of a compound eye display device according to another embodiment of the present invention.

6 is a flowchart showing the operation of the apparatus of FIG.

FIG. 7 is a diagram showing a drive signal inside the liquid crystal display unit.

[Explanation of symbols]

1a, 1b: signal input section, 3a, 3b: liquid crystal display section (LCD), 5a, 5b: decoder section, 7a, 7b: signal processing section, 9a, 9b: driver section, 11a, 11b:
Photometric device, 13: control unit, 14: power supply, 15: power switch, 16: image signal generation unit, 17: memory, 18: memory control unit, 19: timer.

Claims (9)

[Claims] 1. A plurality of liquid crystal display means for displaying image information, and a liquid crystal drive means capable of generating drive signals for driving the plurality of liquid crystal display means and changing the amplitude of the drive signals. A compound eye display device having a common electrode potential generating means for applying a common electrode potential to the plurality of liquid crystal display means, image signal generating means capable of generating at least one or more adjusting image signals, A photometric means for measuring the brightness of the liquid crystal display means, and first, an image signal for common electrode potential adjustment is supplied to each of the liquid crystal display means from the image signal generating means via the liquid crystal drive means, and the photometric measurement at this time is performed. The common electrode potential is adjusted based on the output of the means, and then the plurality of liquid crystal display means are provided to the plurality of liquid crystal display means through the plurality of liquid crystal drive means. Multi-eye display device characterized by having a control means for adjusting the drive signal amplitude in the plurality of drive means based on an output of said plurality of light measuring means supplies a motion signal amplitude adjustment image signal. 2. The adjustment of the common electrode potential is such that the image signal generating means outputs a halftone image, the brightness of the liquid crystal display means at that time is periodically measured by the photometric means, and the measurement result is obtained. 2. The compound-eye display device according to claim 1, wherein the common electrode potential is adjusted so that is constant. 3. The compound eye display device according to claim 2, wherein a cycle of measuring the brightness of the liquid crystal display means by the photometric means is the same as a cycle of inverting the polarity of the liquid crystal drive signal. 4. The amplitude of the liquid crystal drive signal is adjusted by first generating a black image signal by the image generating means, measuring the brightness of the liquid crystal display means at that time by the photometric means, and measuring the brightness of the liquid crystal display means. After adjusting so that the difference in luminance is minimized, the image signal generating means outputs 100% white.
The compound-eye display device according to claim 1, wherein an image is output and adjustment is performed so that a difference in brightness between the plurality of liquid crystal display means is minimized. 5. The compound eye display device according to claim 1, wherein the adjusting operation is performed immediately after the power of the compound eye display device is turned on. 6. The compound eye display device according to any one of claims 1 to 4, wherein the adjusting operation is performed every time a predetermined time elapses, not when the power is turned on. 7. The method according to claim 1, further comprising instruction means for instructing the adjusting operation, wherein the control means performs the adjusting operation when the adjusting operation is instructed by the instructing means. A compound eye display device according to any one of the preceding claims. 8. A storage means for storing various adjustment data of the compound-eye display device, and a measuring means for measuring a drive time of the liquid crystal display means, wherein the storage means stores the drive time of the liquid crystal display means. By recording the total,
When the driving time of the liquid crystal display means reaches a predetermined time when the compound eye display device is powered on, the adjustment operation is performed, the adjusted value is stored in the storage means, and the liquid crystal display 2. The compound eye display device according to claim 1, wherein when the drive time of the means does not reach a predetermined time, the common electrode potential and the amplitude of the liquid crystal drive signal are adjusted according to various data stored in the storage means. 5. The compound eye display device according to any one of to 4. 9. A plurality of liquid crystal display means for displaying image information, and a liquid crystal drive means capable of generating drive signals for driving the plurality of liquid crystal display means and changing the amplitude of the drive signals. In a method of adjusting a drive signal of a compound eye display device having a common electrode potential generating means for applying a common electrode potential to the plurality of liquid crystal display means, it is possible to generate at least one adjustment image signal. Image signal generating means and photometric means for measuring the brightness of the liquid crystal display means, the common electrode potential is adjusted individually for the plurality of liquid crystal display means, and then the plurality of liquid crystal display means are adjusted. A driving signal adjusting method for a compound eye display device, characterized in that a liquid crystal driving signal is adjusted so that a difference in luminance becomes small.